Electromagnetic switch



Nov. 17, 1931- F. J. CALLINGHAM ELECTROMAGNETIC SWITCH Filed Feb. 17,1931 2 Sheets-Sheet l NOV. 17, 1931. CALUNGHAM 1,832,477

ELECTROMAGNETIC SWITCH Filed Feb. 17, 1931 2 Sheets-Sheet 2 Figure 2.

Patented Nov. 17, 1931 UNITED STATES FREDERICK JAMES CALLINGHAM, OFBRIGHTQN, ENGLAND ELECTROMAGNETIC SWITCH Application filed February 17,1931, Serial No. 516,417, and in Great Britain February 8, 1930.

This invention relates to, and has for its object the provision ofimprovements 1n, electromagnetic switches.

The inventionconsist-s broadly in the arrangement according to which themagnet is suspended between two pivot bearings. In order that theinvention may be the more clearly understood, a switch in accordancetherewith will now be described reference being made to the accompanylngdrawings, wherein Figure l is a front elevation of said switch.

Figure 2 is a side elevation of the same.

Figure 3 is a section on line ABCD of Figure 4 is aside elevation, shownin section' on line GH of Figure 5 of the elements whereby the magnet ismounted.

Figure 5 is a section on line EF of Figure 4;

Referring to the drawings the magnet 1 is in the form of the letter Eand carries the winding 2 on the centre limb. The

three polar ends thus formed have their surfaces levelled to a commonplane and. the armature 3 takes the form of an oblong piece having aplane surface adapted when said armature isattracted to rest flush onthese three surfaces. 7

The magnet 1 is fixedly located in the following way y In the firstplace it is supported upon a support which permits adjusting movement ofthe magnetwith respect thereto about anaxis XX at right angles to thegeneral plane of the magnet and located in the plane of the surfaces ofthe polor-ends a convenient distance outside the geometrical limits ofthe magnet. in the second place it is supported upon a suppbrt which issuch as to permit universal adjusting movement of the magnet withrespect thereto about a point Y beyond its geometrical limits theopposite end and, say, in the centre line of the back or connectinglimb. in construction said axis XX and/or said point Y are arranged insuch a way that during mounting or ad justing of the magnet they cantake up the position required by the unconstrained d mensions of themagent and itwill thus be seen that said magnet is fixedly locatedwithout the possibility of its being distorted.

The armature 3 is universally pivoted about the point Z at, say, itscentre ofgrav ity to an armature carrier 4 one end of which is pivotedabout the aforesaid fixed axis XX. This armature carrier 4 has rigidlymounted thereon, in a manner which will be clear from the drawings, aninsulating bar 5, which in turn carries, through the medium of resilientarms 6, the tour moving contacts {I of the switch, Thus in the usual waywhen the magnet winding 2 is energized the armature 3 is attracted andthe carrier 4 is turned about the axis XX thereby pressing the movablecontacts 7 against the respective fixed contacts (not shown), the arms6' being flexed to ensure good contact. When the winding 2 is deenergized the resilient arms 6 start the return movement which iscompleted by gravity.

, Describing the constructional details, the

magnet 1 has a pair of identical plates 8 secured flush against therespective flanks thereof, which plates conform to the E shape of themagnet except that they have lugs 8a and 8b projecting at the respectiveends The lugs 8a have a pin 9 passing transversely through them and alsothrough two upright, arms 10 of a bracket mounted on a fixed panel 13.In this way the magnet 1 is supported about the aforesaid fixed axisX-X.

The lugs have a pin 11 passing through them and also through a bore holein the enlarged head 12 oi a bolt which is bolted to said fixed panel13. This bore hole is counter bored at both ends as shown so that thepin11 only bears in the centre portion, andin this way the magnet isuniversally supported about the aforesaid fixed point Y.

The bolt head 12 and/or the bracket carrying the'arms 10 are not screweddown until after the connection to the magnet is established and it willthus be seen that the bolt and/or the bolts securing the bracket will beable to adjust themselves to some extent within the bolt holes throughthe panel 13 and thus as before stated the magnet will be rigidly fixedin such a way as to be free from distortion.

When the magnet 1 is mounted in position the back or connecting limb isparallel and close to the panel as shown.

The armature 3 consists of a number of laminations clamped on eitherside of a centre plate 14 by means of two outside plates 15 which areheld together by means of rivets passing through the laminations of allthree plates. The armature carrier 4 consists of a channel section leverand the armature 3 is pivoted between the channel walls of this lever bymeans of a pivot pin 16. This armature carrier is rotatable about theaforesaid axis X-X by being pivoted about the same fixed pin 9 to whichthe side plates 8 of the magnet are pivoted.

The bearing of the armature 3 on the pin 16 is taken by the centre plate14 only, the holes in the plates 15 and in the laminations beingconsiderably larger than said pin 16. Thus said armature 3 as well asbeing oscillatable about the axis of said pin 16 is also oscillatablewithin limits about any diameter of the bearing hole in the centre plate14:. In other words said armature is universally pivoted about the pointZ at the centre of said bearing hole and is thus-free to moveuniversally in finding its seating against the magnet. This freedom isaugmented by virtue of the fact that the pivoting of the armaturecarrier 4 about the pin 9 is such that a limited amount of rocking andsideway movement as well as rotary movement is permitted.

The armature carrier is prevented from falling away from the magnetbeyond a given limit by means of a plate 17 mounted as shown on the head12.

Two air gaps 18 are formed in the magnet core, one between each of theouter limbs and the centre limb. In this way residual magnetism in thecore is prevented.

Additional (or they may be alternative) air gaps are formed in thearmature one on each side of the centre limb.

What I claim and desire to secure by Letters Patent is 1 1. In anelectromagnetic switch, a magnet supported upon two supports, one ofsaid supports being such as to permit universal adjusting movement ofthe magnet with respect thereto.

2. In an electromagnetic switch, a magnet supported upon two supports,one of saidsupports being such as to permit universal adjusting movementof the magnet with respect thereto, the other support being such as topermit adjusting movement of the magnet with respect thereto about asingle axis only.

3. In an electromagnetic switch, a magnet, a pair of plates one securedon either side of said magnet and having portions extending beyond thelimits of the magnet, said extending portions being supported upon twosupports, one of said supports being such as to permit universaladjusting movement of the magnet'with respect thereto.

4:. In an electromagnetic switch, a magnet supported upon two supports,one of said supports being such as to permit universal adjustingmovement of the magnet with respect thereto, and a universally pivotedarmature cooperating with said magnet.

5. In an electromagnetic switch, a magnet supported upon two supports,one of said supports being such as to permit universal adjustingmovement of the magnet with respect thereto, and a universally pivotedarmature cooperating with said magnet, said armature being pivoted aboutits center of gravity.

6. In an electromagnetic switch, an armature, and means for supportingsaid armature at its center of gravity for universal movement.

7. In an electromagnetic switch, a magnet supported upon two supports,one of said supports being such as to permit universal adjustingmovement of the magnet with respect thereto, the other support beingsuch as to permit adjusting movement of the magnet with respect theretoabout a single axis only, and an armature cooperating with said magnet,said armature being mounted to swing about the axis of the secondsupport.

Signed at London, England, this 6t day of February, A. D. 1931.

FREDERICK JAMES CALLINGHAM.

